body {
        font-family: Arial;
        margin: 0;
        background: #f5f7fb;
        color: #333;
      }
      header {
        background: #0f172a;
        color: white;
        padding: 20px;
      }
      nav a {
        color: white;
        margin-right: 15px;
        text-decoration: none;
      }
      .container {
        max-width: 1000px;
        margin: auto;
        padding: 40px 20px;
      }
      .hero {
        text-align: center;
        padding: 60px 20px;
      }
      .features {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 20px;
      }
      .feature {
        background: white;
        padding: 20px;
        border-radius: 8px;
        box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
      }
      .notice {
        background: #fff7e6;
        border-left: 5px solid orange;
        padding: 15px;
        margin-top: 30px;
      }
      footer {
        background: #0f172a;
        color: white;
        text-align: center;
        padding: 20px;
        margin-top: 40px;
      }